The present invention represents a unique concept in the field of electrically-activated multilamp photoflash units. As will be described, the photoflash unit of the invention is capable of providing as many or more total flashes per unit as available from most products available today in a compact, miniaturized package possessing a total volume equal to only a fraction of such products. In addition, the invention is capable of operating with greater efficiency than existing units by providing significantly greater levels of lamp output per package volume allocated for each lamp than said currently sold products.
Typical examples of electrically-activated units on today's market are described and illustrated in U.S. Pat. Nos. 3,857,667 (Vetere et al), 4,017,728 (Audessee et al), and 4,164,007 (Audessee et al). The product illustrated in 3,857,667 is commonly referred to in the industry as a "flash bar" and includes two opposing linear arrays of electrically-activated lamps encased in a plastic housing. Subsequent to flashing of the lamps in one linear array, the device must be reversed and the remaining lamps then connected for firing. The "flash bars" available today typically possess a width (length) in excess of four inches, a height of about one and one-half inch, and a thickness (or depth) of about one-half inch. The unit in 4,017,728 is popularly referred to in the industry as a "flip-flash" and contains a total of eight high voltage flash lamps arranged in a vertically oriented planar array with connecting devices at opposite ends of the unit's plastic housing. The device must be inverted to assure ignition of all lamps therein. The "flip-flash" typically has an overall length in excess of five inches, a width in excess of one and one-half inch, and a thickness (depth) of about one-half inch. The multilamp unit described in 4,164,007 constitutes a more recent version of the "flip-flash" product, providing a total of ten lamps in a package possessing similar exterior dimensions to those above. This unit must also be inverted to achieve ignition of the entire array of lamps.
While it is known in the art that the above multilamp devices operate with a relatively high degree of reliability, it is understood that due to the relatively large size (total volume) of each device, carrying of several such units may prove somewhat cumbersome and inconvenient to the average photographer. In addition, the requirement that such devices be of the sizes mentioned above and heretofore deemed necessary in turn necessitates the utilization of correspondingly large quantities of material to produce same, thus adding to manufacturing costs thereof.
It is believed, therefore, that a multilamp photoflash unit which is extremely small in total external volume in comparison to existing such devices and also capable of providing at least an equal number of intense flashes per unit would constitute a significant advancement in the art.
It is also believed that such a unit which is capable of sequentially igniting all of the lamps therein without the need for inverting or reversing the unit, as heretofore required in prior art units such as those defined above, would constitute an art advancement. Several additional notably advantageous features provided by the instant invention over the present art, including the provision of significantly greater levels of lamp illumination per package volume allocated for each lamp, are described below and also deemed supportive of the contention that the invention represents a truly significant advancement in the current state of the art.